Achilles de kiiotinsky



a -EII Patented h1g4, 1896.

mummy- Fig: 5

A. DE KHOTINSKY.

TELEPHONE SUBSTATION APPARATUS.

(No Model.)

Inventor,

UNITED STATES PATENT Orricn.

AOHILLES DE KIIOTINSKY, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE AMERICAN BELL TELEPHONE COMPANY, OF SAME PLACE.

TELEPHONE-SUB STATION APPARATUS.

SPECIFICATION forming part of Letters Patent No. 565,080, dated August 4, 1896.

Application filed May 23, 1896. Serial No. 592,752. (N0 model.)

To ctZZ whom it may concern.-

Be it known that I, AonILLns DE Knornv- SKY, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain Improvements in Telephone- Suhstation Apparatus, of which the following is a specification.

The invention relates to apparatus used at the subscribers station in a telephone system in which the telephone-tranemitter and signal-sending device at such stations have a common source of current supply.

The invention consists in the combination, with such transmitter, signaling device, and common source of current supply, of an in duction coil which has dififierent ratios of transformation according as it is operated in association with the transmitter or the signalin g device.

The electromotive force required for the operation of the transmitter is not as great as that required for the operation of the signalsendin gdevice. hen, therefore, a transmitter and its associated signal-sending device have the same source, it becomes necessary to amplify the original electromotive force of such source to a greater extent when sending signals than when operating the transmitter. I proceed to describe apparatus by which I have accomplished this result.

Figure 1 is a diagrammatic sketch showing a telephonesubstation equipped according to my invention, there also being shown, as will hereinafter appear, a portion of the apparatus used at the central station. Fig. 2 is a diagrammatic sketch showing the same apparatus at the subscribers station, but at a different stage of its operation, and also showing a different condition of apparatus outside of the subscribers station. Fig. 3 is a modification, and Fig. T a detail of Figs. 1 and 2.

Confining the description for the present to Figs. 1 and 2, A is the substation, (J the central station, and L the main circuit.

T is the telephone-transmitter.

R is a rotary commutator or currcnt-reverser, serving in this instance as the signalsending device. I

B islthe source of current supply, and I an induction-coil having, as shown, a single primary winding 17, and in series with each other a secondary winding 2 and a tertiary winding 3, both wound in the same direction.

II is a switch formingthe telephone support or hook for the receiving-telephone T 'When the receiving-telephone is upon the hook, the switch I-I rests upon contact-points 0 c makin g electrical connection therewith; but when it is not upon the hook the switch is in contact with points 0 c, and 0 its stem makin electrical connection with. two of them, 0" and c.

In the drawings the hook-switch II is shown as three levers, but in actual construction there is but a single lever pivoted at lawhcre it is in permanent electrical connection with one side of the main circuit L and with one end of the primary 1) of the induction-coil. It also makes an electrical connection between a conductingplate 6, carried by the switch-lever but insulated therefrom, and the third upper contact-point This plate e is in permanent electrical connection by a conductor 20 with the other end of the primary p of the induction-coil, and bya second conductor 10 with one of the contact-springs t of the current-reversing device R. A second contact-spring i is, by conductor of, in permanent connection with point 0. Conductor w unites contact-point with one electrode of the telephone-transmitter T, as shown. Conductor 1.0 connects the other electrode of the transmitter with one pole of the battery or other source of current supply B, while w connects the other pole of said source with contact-point c Conductors 10 and 10 respectively connect terminal on of the rotary current-reverser R with conductor 10 at a point between T and B and terminal m with. contact-point 0 The conductor w connects the secondary 2 and tertiary 3 of the induction-coil I at the point of their union with contact-point 0 The other end of the secondary 2 is in permanent connection with the side r of the main circuit L, while the other end of the tertiary 3 is in permanent connection, by conductor ro with contact-point 0 In practice the tertiary 3 is wound with a larger number of turns than the secondary 2.

M is the subscribers bell, bridged between the two sides of the main circuit L, as shown.

TOO

At the central station, Fig. l, J isthe sub-* scribers spring-jack or-switch-socket, and a" his calling-annunciator.

In Fig. 2 two subscribers circuits are represented as united for conversation, a being the disconnecting-emuunciator, and T the distant subscribers telephone.

Normally the receiving-telephone T is upon the switch-hook H and the two contactsprings 2 and t of the current-reverser R are upon non-conducting segments of the said reverser. Under these conditions the source of current supply hasits circuit open, both through the transmitter T and through current reversing or changing device R, while the main circuit is closed through the receiving-telephone 'l and the secondary and tertiary windings of the induction-coil, the bell M being in a bridge of the main circuit in parallel withthesaid ind uction-coil windings.

The line being in the normal condition shown in Fig. 1, the subscriber at station A to send a call-signal turns the crank of the cu-rrent reverser R, causing the operation of the-annunciator a at the central station. The local cal-lingcircuit' may be thus traced, beginning at the positive pole of the battery: by conductors w and 10 through terminal m of conducting-segmentd and contact-spring t of the current-reverser R, and by conductor r0 lever-hook H, primary p of the inductioncoil I, conductors w and 20 contact-spring t, segment (1 terminal m, and conductors 10 and 10 to the other pole of the battery; As the crank is turned the reversals of current produced in theprimary p of the induction scribe the-inain circuit further than to say that the tertiary 3 of the induction-coil is now out out, as shown.

In the modification illustrated by'Fig. 3 a push-button or current changing or reversing key is substituted for the rotarycurrentreverser, and the said key performs also some of the functions exercised in Figs. 1 and 2 by the telephone switch-hook H; but this involves no change either in the general mode of operation min the result to be attained.

R is the current-changing keysurmounted by a manipulating-button P. It is so placed with reference to the contact-springs m, m and m that it controls the connection of m and 'm, with their respective contact-points t, 6 t and t and the connection of m with the point Normally the talking-circuit of the second ary 2 of the induction-coil is open at c and is controlled by the hook-switch H the receiving-telephone T being contained therein, between the said point 0 and one terminal of the said secondary, the other terminal thereof being in permanent electrical connection with the main-circuit conductor 0. The main signaling-circuit, including the secondary and tertiary windings 2 and 3 of the induction coil, is also open at 0 and when closed by the operation of the key R the free end of the tertiary coil 3 is electrically united with the main-oircuit conductor r The contact-spring m, representing one pole of the battery, is free from contact with either of its pointst or 25*, and the contact-spring m representing the otherpoleof the battery, is in contact with point t and out of contact with point 15 The key R isoperated 'bypressure'on the button P and' is restored whenthe pressure ceases by a helical spring (not shown) in a manner well understood. When the key is depressed to send the signal, it successively makes contact between spring wa and makescontact between spring m and point t, breaks the existing contact between m and t and also that justformed between on and If, and finally'makes contact between m and i and between m and F. The first of these actions results in closing the main circuit through the secondaryandtertiary of the induction-coilin series, the second'in closingthe local circuit of the source B through the primary '1) of the induction-coil: third, in again opening the primary and battery circuitat both poles, thus interrupting the flow of current through the primary winding, and, fourth, in once moreclosing the said battery-circuit with poles reversed. permitting the battery-currentagain' to flow through the primary 1? but in the reverse direction. A

vVhen pressure is removed from thekey P. it returns to its'normalposition, making the above changes once more, but in reversed order, and thereversals of currentwhich occur in the primary 1). induce an oscillatory current of high electromotive force in the secondary 2 and tertiary 3, which, passing to the line, actuate the signal a at the distant stations exactlyas in the plan indicated by Figs. 1 and 2.-

It is obvious that all of the'chan ges described above could be brought about, if desired, by contacts to be madea-nd broken by the movements of thetelephone-hook-switch lever, so that they might be effected automatically when the telephone is removed for use or replaced.

Since an important feature of my invention is an induction-coil whose ratio of transformation is greater when employed to send signals than when used in talking, it isobvious that I am not restricted to an inductioncoil having the constructi on des'cribedabove.

I may, for instance, employ an inductioncoil with a single primary and several sec- IIS ondaries, connecting the said secondaries in parallel with each other for telephonic transmission and in series with each other to send signals; or I may wind my coil with a single secondary and several primaries, giving a high ratio of transformation to send signals when the primaries are connected in parallel, and a low ratio of transformation to transmit conversation when they are connected in series.

Having now fully described my invention and its mode of operation, I claim In a telephone-station apparatus, the combination with a telephone-tramsmitter, a current-changing signal-sending device, and a source of current supply common to both, of an induction-coil for transforming the currents of said source of supply in both talking and signaling, having different ratios of transformation, according as itis operated in association with the transmitter, or with the signaling device. 

